ARM: OMAP: Add method to register additional I2C busses on the command line, v2
Jarkko Nikula [Tue, 24 Mar 2009 01:07:48 +0000 (18:07 -0700)]
This patch extends command line option "i2c_bus=bus_id,clkrate" so that
it allow to register additional I2C busses that are not registered with
omap_register_i2c_bus from board initialization code.

Purpose of this is to register additional board busses which are routed
to external connectors only without any on board I2C devices.

Cc: linux-i2c@vger.kernel.org
Signed-off-by: Jarkko Nikula <jarkko.nikula@nokia.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

Documentation/kernel-parameters.txt
arch/arm/plat-omap/i2c.c

index d775076..ef9827f 100644 (file)
@@ -831,6 +831,8 @@ and is between 256 and 4096 characters. It is defined in the file
                               terminal devices. Valid values: 0..8
 
        i2c_bus=        [HW] Override the default board specific I2C bus speed
+                            or register an additional I2C bus that is not
+                            registered from board initialization code.
                             Format:
                             <bus_id>,<clkrate>
 
index aa70e43..a303071 100644 (file)
@@ -98,6 +98,8 @@ static const int omap34xx_pins[][2] = {
 static const int omap34xx_pins[][2] = {};
 #endif
 
+#define OMAP_I2C_CMDLINE_SETUP (BIT(31))
+
 static void __init omap_i2c_mux_pins(int bus)
 {
        int scl, sda;
@@ -133,6 +135,31 @@ static int __init omap_i2c_nr_ports(void)
        return ports;
 }
 
+static int __init omap_i2c_add_bus(int bus_id)
+{
+       struct platform_device *pdev;
+       struct resource *res;
+       resource_size_t base, irq;
+
+       pdev = &omap_i2c_devices[bus_id - 1];
+       if (bus_id == 1) {
+               res = pdev->resource;
+               if (cpu_class_is_omap1()) {
+                       base = OMAP1_I2C_BASE;
+                       irq = INT_I2C;
+               } else {
+                       base = OMAP2_I2C_BASE1;
+                       irq = INT_24XX_I2C1_IRQ;
+               }
+               res[0].start = base;
+               res[0].end = base + OMAP_I2C_SIZE;
+               res[1].start = irq;
+       }
+
+       omap_i2c_mux_pins(bus_id - 1);
+       return platform_device_register(pdev);
+}
+
 /**
  * omap_i2c_bus_setup - Process command line options for the I2C bus speed
  * @str: String of options
@@ -154,11 +181,33 @@ static int __init omap_i2c_bus_setup(char *str)
        if (ints[0] < 2 || ints[1] < 1 || ints[1] > ports)
                return 0;
        i2c_rate[ints[1] - 1] = ints[2];
+       i2c_rate[ints[1] - 1] |= OMAP_I2C_CMDLINE_SETUP;
 
        return 1;
 }
 __setup("i2c_bus=", omap_i2c_bus_setup);
 
+/*
+ * Register busses defined in command line but that are not registered with
+ * omap_register_i2c_bus from board initialization code.
+ */
+static int __init omap_register_i2c_bus_cmdline(void)
+{
+       int i, err = 0;
+
+       for (i = 0; i < ARRAY_SIZE(i2c_rate); i++)
+               if (i2c_rate[i] & OMAP_I2C_CMDLINE_SETUP) {
+                       i2c_rate[i] &= ~OMAP_I2C_CMDLINE_SETUP;
+                       err = omap_i2c_add_bus(i + 1);
+                       if (err)
+                               goto out;
+               }
+
+out:
+       return err;
+}
+subsys_initcall(omap_register_i2c_bus_cmdline);
+
 /**
  * omap_register_i2c_bus - register I2C bus with device descriptors
  * @bus_id: bus id counting from number 1
@@ -173,9 +222,6 @@ int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
                          unsigned len)
 {
        int err;
-       struct platform_device *pdev;
-       struct resource *res;
-       resource_size_t base, irq;
 
        BUG_ON(bus_id < 1 || bus_id > omap_i2c_nr_ports());
 
@@ -185,24 +231,9 @@ int __init omap_register_i2c_bus(int bus_id, u32 clkrate,
                        return err;
        }
 
-       pdev = &omap_i2c_devices[bus_id - 1];
-       if (i2c_rate[bus_id - 1] == 0)
+       if (!i2c_rate[bus_id - 1])
                i2c_rate[bus_id - 1] = clkrate;
+       i2c_rate[bus_id - 1] &= ~OMAP_I2C_CMDLINE_SETUP;
 
-       if (bus_id == 1) {
-               res = pdev->resource;
-               if (cpu_class_is_omap1()) {
-                       base = OMAP1_I2C_BASE;
-                       irq = INT_I2C;
-               } else {
-                       base = OMAP2_I2C_BASE1;
-                       irq = INT_24XX_I2C1_IRQ;
-               }
-               res[0].start = base;
-               res[0].end = base + OMAP_I2C_SIZE;
-               res[1].start = irq;
-       }
-
-       omap_i2c_mux_pins(bus_id - 1);
-       return platform_device_register(pdev);
+       return omap_i2c_add_bus(bus_id);
 }